KIC 5197256: an eclipsing binary containing a delta Scuti variable star

This paper reports analysis of an eclipsing binary system KIC 5197256 with a delta Sct variable component. Utilizing light-curve modeling, several stellar parameters are derived, e.g., temperature, mass, and mass ratio. The O - C diagram is a straight line with a negative slope which means that its period is almost constant for about 2 yr. Frequency analyses are performed for the residual light curve after subtracting the binary variations. The frequency spectrum reveals that one component star is a delta Scuti variable. Large frequency separation is cross-identified with the histogram graph and the Fourier transform method. Based on the large separation and density relationship, the mean density of the delta Sct component is estimated to be 0.05 g.cm(-3). Five frequencies with the same frequency spacing in the range of 25 d(-1) - 34 d(-1) are detected. Statistically, the pulsation amplitudes of delta Sct stars increase with decreasing of rotations, so we propose that KIC 5197256 might have a relatively large rotational velocity, and the frequency f(10) might be the rotation frequency.